Substrate response to atomic scattering from solid surfaces

A technique for calculating the response of the substrate to atomic scattering from solid surfaces is presented. It utilizes a time-dependent phonon Green's function approach to calculate the propagation into the substrate of a disturbance induced by an atom-surface collision and it can, in principle, be incorporated into a recently introduced subspace Hamiltonian technique for calculating atomic forces from electronic energies. It therefore promises to be useful in conjunction with computer simulations of atomic motion at solid surfaces. The method is illustrated in the case of a simple model where the propagation of the disturbance from the collision can be calculated in terms of simple functions.